This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
A communication system can be seen as a facility that enables communication sessions between two or more entities such as user equipment and/or other nodes associated with the communication system. The communication may comprise, for example, communication of voice, data, multimedia and so on. A session may, for example, be a telephone call between users or multi-way conference session, or a communication session between user equipment and an application server (AS), for example a service provider server. The establishment of these sessions generally enables a user to be provided with various services.
A communication system typically operates in accordance with a given standard or specification which sets out what the various entities associated with the communication system are permitted to do and how that should be achieved. For example, the standard or specification may define if the user, or more precisely, user equipment is provided with a circuit switched service and/or a packet switched service. Communication protocols and/or parameters which shall be used for the connection may also be defined. In other words, a specific set of “rules” on which the communication can be based on needs to be defined to enable communication by means of the system.
One of the “rules” of the communication system is the requirement to identify and to authenticate the user of the user equipment when in communication with the wireless communications system. In many user equipment a user identification module (UID) is used to provide the mobile phone with relevant information to transmit to the communications system to carry out this action. In typical universal mobile telecommunications systems (UMTS) the function of the user identity module is carried out by the insertion of a removable universal integrated circuit card (UICC). The UICC is commonly also known as a chip card and typically consists of a CPU, read-only memory, random-access memory, and also some electronically erasable programmable read-only memory (EEPROM). Typically, the memory allows the storage of a few hundred kilobytes of data. Furthermore, the smart card has various input/output circuitry to enable it to talk to the outside world.
The UICC used in the known UMTS mobile telephone networks contains an application such as the universal subscriber identity module (USIM) which stores user subscriber information, authentication information and provides storage base for text messages. For example, for authentication purposes, the USIM stores a long term pre-shared secret key K which is shared with an authentication centre (KuC) in the network. The USIM also verifies a sequence number which must be within a range using a window mechanism to avoid replay attacks.
Similarly, the Global Standard for Mobile (GSM) mobile telephone networks use an UICC also known as a subscriber identity module (SIM) which securely stores the key identifying the mobile phone service subscriber as well as subscription information, preferences and text messages.
The UICC/SIM card is required to interface with the user equipment. Conventional interfaces between the UICC/SIM card and the user equipment have a fixed upper bandwidth—the existing interfaces cannot transfer data faster than approximately 600 Kbits per second. This upper bandwidth can lead to delays in extracting data such as cryptographic keys from the UICC or for reading or writing of real time data to the limited capacity memory on the UICC.
Faster interface designs have been proposed which can transfer data at up to 8 Mbits per second.
The universal serial bus (USB) interface proposal is based upon the physical and logical interface procedure commonly used within the personal computing world for connecting components together. The USB proposal although being flexible and capable of providing speed of 12 Mbits per second, is inherently complex and requires a physical interface implementation of a pair of twisted cables to communicate data. This added complexity adds cost and weight in physical terms and also requires the implementation of lower efficiency methods of transferring data over current slow interfaces.
The multimedia card (MMC) interface proposal is another based on a technology used in a complementary field—this technology currently used to transfer data to and from multimedia memory cards. The secureMMC 2.0 interface layer specification is publicly available from the European Telecommunications Standards Institute (ETSI) website. This interface proposal though is also flawed in that implementations of the interface is not well developed, especially compared with the USB interface.
The synchronous T=1 interface proposal is based on a combination of the ETSI standard TS 102 221 v7.5: Smart Cards: UICC-Terminal interface; Physical and logical characteristics, which builds upon the asynchronous T=1 interface proposed in ISO/IEC 7816-3: Identification cards—Integrated Circuit Cards—Part 3: Cards with contacts: Electrical interface and transmission protocols. This interface is also relatively new and undeveloped, especially compared with the USB interface.
Embodiments of the present invention aim to address these problems associated with the proposed interfaces.